Automatic suture fixation apparatus and method for minimally invasive cardiac surgery

ABSTRACT

An apparatus for automatically fixing sutures used in the surgical replacement of a heart valve, including a first cylinder having a first end and a second end and an interior surface and an exterior surface, and first means for securing fixing suture formed on the exterior surface adjacent to the second end of the first cylinder. The apparatus also includes a second cylinder having second means for securing fixing suture formed on an interior surface of the second cylinder, such that the second means corresponds to and fixedly engages the first means for securing fixing suture, and the first means and the second means secure fixing sutures therebetween.

This application is a divisional application of and claims priority fromU.S. patent application Ser. No. 09/987,976, which was filed on Nov. 16,2001, which claims priority from U.S. Provisional Patent Application No.60/248,837, which was filed on Nov. 16, 2000, the disclosures of whichare incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to apparatus for automatic suture fixation andmethods for minimally invasive cardiac surgery employing such apparatus.In particular, the invention relates to apparatus for automatic suturefixation including a first cylinder fitted with first securing means onits exterior surface and a second cylinder with second securing means onits interior surface, whereby sutures may be secured between thesecylinders when the corresponding securing means engage. Further, methodsfor minimally invasive cardiac surgery employing such apparatus mayinclude the steps of threading the sutures used to secure a replacementheart valve over the exterior surface of the first cylinder and over theinterior surface of the second cylinder, applying pressure against thefirst cylinder to secure it against the replacement valve, and applyingtension against the sutures to achieve a blood-tight seal between thereplacement valve and the heart, before securing the sutures between thefirst and second cylinders.

2. Description of Related Art

Current methods of placing replacement heart valves, includingprosthetic valves, harvested pig valves, and human donor valves, requirethe careful placement and tying-off of numerous sutures. In heart valvereplacement surgery, a damaged, defective, or diseased heart valve isremoved to provide an annulus for securing a replacement valve. In orderto prepare the annulus to receive the replacement valve, tractionstitches may be placed through the annulus from both the superior andinferior aspects of the annulus. By applying tension to these sutures,the annulus may be better exposed to facilitate positioning of thereplacement valve.

Replacement valves may be fitted with a sewing ring, which surrounds thevalve and allows it to be more tightly secured to the annulus withoutpenetrating the valve structure. A surgeon may use interrupted mattressstitching to secure the replacement valve to the annulus. Mattressstitches are chosen to allow more exact tissue to replacement valve edgeapproximation.

The individual sutures may be made from a 2/0 synthetic material and arefitted with curved needles at each end. The natural curve of theseneedles aids the surgeon in guiding the needle tips away from coronaryarteries including the coronary sinus and in avoiding inadvertentpenetration of the fat of the atrioventricular groove. In addition, thesutures are preferably selected, such that alternating colors of suturemay be used to secure the replacement valve to the annulus. By usingalternating colors of suture, the surgeon may more readily keep track ofthe sutures, as he or she ties them off to secure the replacement valveto the annulus. Alternating suture colors reduces the risk that the endsof discontinuous sutures will be tied together, resulting in animproperly secured replacement value and the possibility of leakage orfailure of the replacement valve.

A holder may be used to position the replacement away from the annuluswhile the annulus is prepared to receive the replacement valve. Thesurgeon applies the sutures, e.g., about 18 to 24 sutures on average,such that the sutures pass through the sewing ring of the replacementvalve and then through the annulus, posteriorly. Pledgets, such ascompressed Teflon® felt pledgets, may be threaded separately onto thesuture to strengthen the attachment of the replacement valve to theannulus. The initial pass from the posterior face of the annulus may becompleted in a counterclockwise direction around the annulus. Thesurgeon then may pass sutures through the anterior face of the annulusand pass the suture through the sewing ring of the replacement valve.This anterior stitching may be completed in a clockwise direction. Byshifting the position of the replacement valve (or the replacement valveholder) with respect to the annulus and by applying tension to thetraction stitches, the surgeon may expose the annulus in the manner thatfacilitates the placement of securing sutures.

Once the surgeon has completed the placement of the sutures, the surgeonmay place tension on the sutures and slide the replacement valve intoposition within the annulus. The surgeon then ties off the sutures inthe order in which they were placed—first the posteriorly placed suturesfollowed by the anteriorly placed sutures. As each suture is tied off,the surgeon reconfirms that the replacement valve remains properlypositioned and securely sealed to the annulus, so that he or she mayattain a blood-tight seal between the replacement valve and the annulus.

Because of the necessity for the careful placement of the replacementvalve within the annulus and the requirement that each pair of sutureends are individually tied, heart valve replacement surgery may belengthy, requiring the patient to spend an extended period of time underanesthesia. Further, because the patient's heart must be stopped duringheart valve replacement surgery, a lengthy surgery requires the patientto spend an extended period with breathing and circulation supported bya heart-lung (or heart by-pass) machine. An extended period underanesthesia and on a heart-lung machine may complicate and delay therecovery process.

In addition, as noted above, the surgeon confirms that the replacementvalve remains properly positioned within the annulus after each pair ofsuture ends is tied, and the surgeon ensures that only continuous sutureends are tied together. Thus, the surgeon needs sufficient room toobserve the suture attachment and the positioning of the replacementvalve and to manipulate the sutures in close proximity to the patient'sheart. This may be extremely difficult to achieve in minimally-invasivecardiac surgery (MICS), in which the surgeon may be required to operatethrough an opening in the patient's chest with a small diameter, e.g.,between about 2 cm and about 3 cm. Further, the patient's heart may bepositioned between about 10 cm and about 12 cm below the chest opening.Larger openings generally increases the risk associated with the surgeryand increase the patient's recovery time. Therefore, in order toaccomplish valve replacements using MICS techniques, surgeons frequentlyresort to a knot tying device to push the suture knots down into thepatient's chest opening.

SUMMARY OF THE INVENTION

Thus, a need has arisen for apparatus and methods, which permit surgeonsto secure sutures within the limitations imposed by MICS. In particular,a need has arisen for apparatus and methods, which permit surgeons toquickly and accurately secure sutures.

It is a feature of the present invention that it permits surgeons tooperate within the extremely confined spaces available in MICS or in themore larger spaces available in more traditional open, heart surgery. Itis an additional feature that the present invention reduces oreliminates suture tying errors by reducing or eliminating the need fortying individual suture pairs. It is yet another feature of the presentinvention that sutures may be trimmed flush with the valve replacementapparatus, thus reducing or eliminating the suture ends as a potentialsource of irritation and eliminating the knots as a possible cause ofleakage or valve replacement failure.

It is an advantage of the present invention that it permits surgicaltime to be reduced, thereby reducing the amount of time that a patientremains under anesthesia and on a heart-lung machine. By reducing eachof these aspects of the surgical procedure, the patient's prospects forrecovery may be improved, and the patient's recovery may be accelerated.It is a further advantage of the present invention that by reducing thetime required to secure the heart valve replacement, the amount of timerequired to complete heart valve replacement surgery may be reduced.This may result in decreased surgical costs due to more efficient use ofsurgical resources, e.g., operating rooms and monitors and anesthesiaequipment; more efficient use of surgeon's time; and shortened hospitalstays after heart valve replacement surgery.

In an embodiment, the invention is an apparatus for automatically fixingsutures used in the surgical replacement of a heart valve. The apparatuscomprises a first cylinder having a first end and a second end and aninterior surface and an exterior surface and a valve sleeve including anannular cuff surrounding the exterior surface adjacent to the first endof the first cylinder. First securing means are formed on the exteriorsurface adjacent to the second end of the first cylinder, and areplacement heart valve is positioned within the valve sleeve. Theapparatus further comprises a second cylinder having second securingmeans formed on an interior surface of the second cylinder, such thatthe second securing means correspond to and are adapted to fixedlyengage the first securing means.

In another embodiment, the invention again is an apparatus forautomatically fixing sutures used in the surgical replacement of a heartvalve. The apparatus comprises a first cylinder having a first end and asecond end and an interior surface and an exterior surface, and a valvesleeve including an annular cuff and a plurality of securing strutssurrounding the exterior surface adjacent to the first end of the firstcylinder. These struts extending beyond the first end of the firstcylinder. First securing means are formed on the exterior surfaceadjacent to the second end of the first cylinder, and a replacementheart valve is positioned within the valve sleeve. the replacement heartvalve has a circumferential outer edge, wherein the circumferentialouter edge is affixed to the valve sleeve. The apparatus furthercomprises a second cylinder having second securing means formed on aninterior surface of the second cylinder, such that the second securingmeans corresponds to and is adapted to fixedly engage the first securingmeans.

In still another embodiment, the invention also is an apparatus forautomatically fixing sutures used in the surgical replacement of a heartvalve. The apparatus comprises a first cylinder having a first end and asecond end and an interior surface and an exterior surface, a valvesleeve including an annular cuff, and a prosthetic heart valvepositioned within the first cylinder and affixed to the valve sleeve.The valve sleeve surrounds the exterior surface adjacent to the firstend of the first cylinder, and first securing means are formed on theexterior surface adjacent to the second end of the first cylinder. Theapparatus further comprises a second cylinder having second securingmeans formed on an interior surface of the second cylinder, such thatthe second securing means corresponds to and are adapted to fixedlyengage the first securing means.

In yet another embodiment, the invention is a method for automaticallyfixing sutures to secure a valve sleeve including an annular cuff and areplacement heart valve, to an annulus formed in a patient's heart. Themethod comprises the steps of removing an existing heart valve, therebyforming an annulus in the patient's heart and placing a first cylinderhaving a first end and a second end and an interior surface and anexterior surface within the annulus. The first cylinder comprises firstsecuring means formed on the exterior surface adjacent to the second endof the first cylinder. The first cylinder includes a valve sleeve havingan annular cuff, such that the annular cuff surrounds the exteriorsurface adjacent to the first end of the first cylinder. The annularcuff of the valve sleeve then is positioned in the annulus and securingthe cuff to the annulus with a plurality of sutures, and the pluralityof sutures are threaded over the exterior surface of the first cylinderand over an interior surface of a second cylinder. The second cylinderhas second securing means corresponding to and adapted to fixedly engagethe first securing means of the first cylinder. Pressure then is appliedagainst the first cylinder, and tension is applied to the plurality ofsutures to ensure a blood-tight seal between the cuff of the valvesleeve and the annulus. The plurality of sutures then may be securedbetween the first cylinder and the second cylinder by engaging the firstsecuring means of the first cylinder with the second securing means ofthe second cylinder.

In yet a further embodiment, the invention again is a method forautomatically fixing sutures to secure a valve sleeve including anannular cuff and a replacement heart valve to an annulus formed in apatient's heart. The method comprises the steps of removing an existingheart valve thereby forming an annulus in the patient's heart,positioning the annular cuff of the valve sleeve in the annulus, andsecuring the cuff to the annulus with a plurality of sutures. The methodfurther comprises the steps of placing a first cylinder having a firstend and a second end and an interior surface and an exterior surfacewithin the valve sleeve, such that the annular cuff surrounds theexterior surface adjacent to the first end of the first cylinder. Thefirst cylinder also comprises first securing means formed on theexterior surface adjacent to the second end of the first cylinder. Theplurality of sutures then are threaded over the exterior surface of thefirst cylinder and over an interior surface of a second cylinder. Thesecond cylinder has second securing means corresponding to and adaptedto fixedly engage the first securing means of the first cylinder.Pressure is then applied against the first cylinder, and tension isapplied to the plurality of sutures to ensure a blood-tight seal betweenthe cuff of the valve sleeve and the annulus. The plurality of suturesthen are secured between the first cylinder and the second cylinder byengaging the first securing means of the first cylinder with the secondsecuring means of the second cylinder.

Other objects, features and advantages of the invention will be apparentto those skilled in the art from the following detailed description ofpreferred embodiments and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood with reference to the followingdrawings of preferred embodiments of the invention, in which:

FIG. 1 depicts an embodiment of the apparatus including a first cylinderand a second cylinder;

FIGS. 2-1 and 2-2 depict cross-sectional views of the first and secondcylinders, including embodiments of the corresponding, first and secondsecuring means;

FIGS. 3-1 and 3-2 depict a plan view of the first cylinder of FIG. 2-2and an enlarged view of a portion of this first cylinder showingcircumferentially arranged suture-relief holes;

FIG. 4 depicts another embodiment of the apparatus including a firstcylinder and a second cylinder, with a valve sleeve surrounding thelower portion of the exterior surface of the first cylinder;

FIG. 5 depicts yet another embodiment of the apparatus including a firstcylinder and a second cylinder, with a valve sleeve having an annularcuff and three securing struts;

FIG. 6 depicts the embodiment of FIG. 5, wherein the securing means ofthe first and second cylinders are snapped into engagement, and thesecured sutures have been trimmed;

FIG. 7 depicts the embodiment of FIG. 4 mounted on a guiding rod;

FIG. 8 depicts the embodiment of FIG. 4 mounted on an insertion deviceincluding a guiding rod, securing member, and urging means;

FIG. 9 depicts an expanded view of the insertion device of FIG. 8;

FIG. 10 depicts the insertion device of FIG. 8, with the urging memberdepressed, such that the second cylinder is snapped into engagement withthe first cylinder; and

FIG. 11 depicts an expanded view of the insertion device of FIG. 10.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, an embodiment of the apparatus 1 is depictedincluding a first cylinder 10 and a second cylinder 20. The material forcylinders 10 and 20 is chosen to be bio-compatible andanti-thrombogenic. Cylinders 10 and 20 may be made from a suitable metalor plastic, such as Delrin® plastic, manufactured by E.I. DuPont deNemours and Co. of Wilmington, Del., pyrolitic carbon, or aTitanium-Nickel (95%-5%) alloy. Cylinders 10 and 20 must sufficientlyrigid to hold the replacement valve securely during its surgicalinsertion, but sufficiently flexible to allow second cylinder 20 to besnapped into place over first cylinder 10. Preferably, first cylinder 10is slightly more rigid than second cylinder 20, so that second cylinder20 may be snapped into place over first cylinder 10.

First cylinder 10 comprises an exterior surface 12 and an interiorsurface 18 and a second (or upper) end 14 and a first (or lower) end 16.Further, first cylinder 10 includes a first securing means 15.Similarly, second cylinder 20 comprises an interior surface 22 and afirst (or upper) end 24. Second cylinder 20 also includes a secondsecuring means 25. Second securing means 25 correspond to and areadapted to engage first securing means 15. For example, first securingmeans 15 may be an annular lip and second securing means 25 may be acorresponding annular groove, or vice versa.

Referring to FIGS. 2-1 and 2-2, cross-sectional views of versions offirst cylinder 10 and second cylinder 20, including embodiments of thecorresponding securing means 15 and 25, respectively. In particular, theversion depicted in FIG. 2-1 is configured to receive a valve sleeve(not shown) with an annular cuff (not shown) around the lower portion offirst cylinder 10. Consequently, first cylinder 10 may have a height ofabout 5.25 mm, and second cylinder 20 may have a height of about 2.49mm.

The valve sleeve may be manufactured from a surgical fabric, such as asurgical fabric selected from the group consisting of a Dacron® fabric,a Teflon® fabric, a Gore-Tex® fabric, and the like. In this version, areplacement valve (not shown), such as a heart valve harvested from ahuman donor or a heart valve harvested from a pig, is attached to thevalve sleeve. For example, the replacement heart valve may include asewing ring by which the valve may be sutured to the valve sleeve.

In the version depicted in FIG. 2-2, first cylinder 10′ again isconfigured to engage second cylinder 20′. Specifically, first securingmeans 15′ engage second securing means 25′. By comparison with FIG. 2-1,it is evident that first cylinder 10′ is shorter than first cylinder 10,and that first cylinder 10′ lacks the portion configured to receive avalve sleeve (not shown) with an annular cuff (not shown) around thelower portion of first cylinder 10′. Although first cylinder 10′ also isconfigured to receive a valve sleeve (not shown) with an annular cuff(not shown), first cylinder 10′ is designed to receive a prostheticheart valve (not shown) within its circumference. Such a prostheticheart valve may be attached directly to the valve sleeve without theaddition of a sewing ring. Consequently, the heights of first cylinder10′ and second cylinder 20′ are substantially the same and substantiallyequal to about 3.25 mm.

Referring to FIG. 3-1, a plan view of another version of first cylinder10′ of FIG. 2-2 is shown. In this version, cylinder 10′ has been adaptedto receive at least one of a plurality of securing sutures (not shown)into each of a plurality of relief holes 30, e.g., 40 relief holesspaced at 9° intervals, arrayed around the exterior surface of firstcylinder 10′. In particular, relief holes 30 may be formed within firstsecuring means 15′, so that the sutures may be tightly secured betweenfirst cylinder 10′ and second cylinder 20′ when first securing means 15′engages second securing means 25′. As discussed below, suture may bepassed through the annular cuff (not shown) and through the annulusformed by the removal of a damaged, defective, or diseased valve fromthe patient's heart. An enlarged view of a portion of first cylinder 10′showing circumferentially arranged, suture-relief holes 30 is shown inFIG. 3-2.

In FIG. 4, another embodiment of the apparatus is depicted includingfirst cylinder 10 and second cylinder 20. In this embodiment, a valvesleeve 40 surrounds the lower portion of exterior surface 12 of thefirst cylinder 10. Valve sleeve 40 includes an annular cuff 42 forsecuring apparatus 1 to an annulus formed in the patient's heart. Asnoted above, valve sleeve 40 may be manufactured from a surgical fabric,such as a surgical fabric is selected from the group consisting of aDacron® fabric, a Teflon® fabric, a Gore-Tex® fabric, and the like.

Referring to FIG. 5, yet another embodiment of apparatus 1 includesfirst cylinder 10, second cylinder 20, and valve sleeve 40′ havingannular cuff 42′ and three securing struts 44′. Valve sleeve 40′ ismanufactured from a surgical fabric, such as a surgical fabric isselected from the group consisting of a Dacron® fabric, a Teflon®fabric, a Gore-Tex® fabric, and the like. In this version, a replacementvalve (not shown), such as a heart valve harvested from a human donor ora heart valve harvested from a pig, is attached to valve sleeve 40′ atsecuring struts 44′. For example, the replacement heart valve mayinclude a sewing ring by which the valve may be sutured to securingstruts 44′.

As shown in FIG. 5 and discussed above, apparatus 1 is secured to theannulus formed in the patient's heart by means of sutures passed throughannular cuff 42′ and the annulus. Suitable suture may be made from a 2/0synthetic material and are fitted with curved needles at each end. Inaddition, as with known methods of securing replacement valves to anannulus formed in a patient's heart, pledgets, such as compressedTeflon® felt pledgets, may be threaded separately onto the suture tostrengthen the attachment of the replacement valve to the annulus.However, because of the importance of attaining and maintaining ablood-tight seal between apparatus 1 and the annulus, and in view of therigid structure of first cylinder 10 and second cylinder 20, thepledgets must not be placed between apparatus 1 and the annulus.

Once annular cuff 42′ is sutured to the annulus the end pairs of eachsuture 100 are passed over exterior surface 12 and first securing means15 of first cylinder 10 and over interior surface 22 and second securingmeans 25. By applying tension to the sutures 100 and pressure to secondend 14 of first cylinder 10, annular cuff 42′ may be tightly sealedagainst the annulus. Once this seal is established, second cylinder 20may be pressed down onto first cylinder 10, so that first sealing means15 may engage second sealing means 25 and thereby seize sutures 100within apparatus 1. Referring to FIG. 6, the embodiment of FIG. 5 isdepicted, wherein the securing means of first and second cylinders 10and 20 are snapped into engagement, and the secured sutures have beentrimmed.

In FIG. 7, the embodiment of apparatus I of FIG. 4 is depicted mountedon a guiding rod 50. Guiding rod 50 includes a rod end piece 52 formedat a first end of guiding rod 50. Rod end piece 52 has six supportbrackets 54 extending from rod end piece 52. and a guiding ring 56affixed to support brackets 54. Ring 56 is adapted to engage second end14 of first cylinder 10. Moreover, interior surface 22 of secondcylinder 20 slidingly engages an exterior surface 55 of each of supportbrackets 54.

Again referring to FIG. 7, at least one eyelet 58 is formed on each ofsupporting brackets 54 for receiving at least one suture 100. Bythreading sutures 100 through eyelets 58, guiding ring 56 may be guidedinto contact with second end 14 of first cylinder 10. Tension applied tosutures 100 and pressure applied against guiding ring 56 to seal firstcylinder 10 and its attached annular cuff 42 against the annulus.

Referring to FIG. 8, the embodiment of FIG. 4 is depicted mounted on aninsertion device 2 including guiding rod 50, a securing member 60, andurging means 80. Securing member 60 includes a rod sleeve 62, whichslidingly engages guiding rod 50. A sleeve end piece 64 is formed on afirst end of rod sleeve 62. Sleeve end piece 64 has six securingbrackets 66, which are adapted to engage second cylinder 20 and whichare angularly offset and positioned to interfit with support brackets54. Insertion device 2 further comprises urging means 80 for slidingsecuring member 60 on guiding rod 50, whereby second securing means 25of second cylinder 20 is urged into engagement with first securing means15 on first cylinder 10. Urging means 80 comprise a handle 82 fixedsubstantially perpendicular to guiding rod 50 and a grip 84 pivotallyattached by a pin 86 to handle 82. When grip 84 is pivoted on pin 86 inthe direction of Arrow A, a levered projection 88 urges securing member60 towards rod end piece 52.

In FIG. 9, an expanded view of insertion device 2 of FIG. 8 is depicted.As described in FIG. 7, interior surface 22 of second cylinder 20slidingly engages an exterior surface 55 of each of support 54. Sleeveend piece 64 has six securing brackets 66, which are adapted to engagesecond cylinder 20 with engaging surfaces 68. As noted above, securingbrackets 66 are angularly offset and positioned to interfit with supportbrackets 54.

Referring to FIG. 10, insertion device 2 of FIG. 8 is depicted withurging member 80 depressed, such that second cylinder 20 is snapped intoengagement with first cylinder 10. Specifically, grip 84 has beenpivoted on pin 86 and thereby depressed against handle 82. Consequently,levered projection 88 is moved in the direction of Arrow B, and leveredprojection 88 contacts securing member 60 urging it toward rod end piece52. As a result, securing brackets 66 interfit with support brackets 54,second cylinder 20 is urged into contact with first cylinder 10. Asindicated in FIG. 11, an expanded view of insertion device 2 of FIG. 10is depicted, showing second cylinder 20 urged into engagement with firstcylinder 10.

In another embodiment, the invention is a method for automaticallyfixing sutures to secure a valve sleeve including an annular cuff and areplacement heart valve to an annulus formed in a patient's heart. Themethod comprises the steps of removing an existing heart valve, therebyforming an annulus in the patient's heart, and placing a first cylinderwithin the annulus. The first cylinder has a first end and a second endand an interior surface and an exterior surface and comprises firstsecuring means formed on the exterior surface adjacent to the second endof the first cylinder. The first cylinder also includes a valve sleevehaving an annular cuff, such that the annular cuff surrounds theexterior surface adjacent to the first end of the first cylinder. Themethod further comprises the steps of positioning the annular cuff ofthe valve sleeve in the annulus and securing the cuff to the annuluswith a plurality of sutures, e.g., 18 to 24 sutures, and threading theplurality of sutures over the exterior surface of the first cylinder andover an interior surface of a second cylinder. As noted above, thesecond cylinder has second securing means corresponding to and adaptedto fixedly engage the first securing means of the first cylinder.Pressure then is applied against the first cylinder, and tension isapplied to the plurality of sutures to ensure a blood-tight seal betweenthe cuff of the valve sleeve and the annulus. The plurality of suturesthen are secured between the first cylinder and the second cylinder byengaging the first securing means of the first cylinder with the secondsecuring means of the second cylinder. Finally, the plurality of suturesare trimmed at a length in a range of about 3 mm to about 5 trim, abovethe second cylinder, and preferably, the plurality of sutures aretrimmed flush with the second cylinder.

In yet another embodiment, the invention is a method for automaticallyfixing sutures to secure a valve sleeve including an annular cuff and areplacement heart valve to an annulus formed in a patient's heart. Themethod comprises the steps of removing an existing heart valve, therebyforming an annulus in the patient's heart, and positioning the annularcuff of the valve sleeve in the annulus and securing the cuff to theannulus with a plurality of sutures. The method further comprises thesteps of placing a first cylinder having a first end and a second endand an interior surface and an exterior surface and comprising firstsecuring means formed on the exterior surface adjacent to the second endof the first cylinder, within the valve sleeve, such that the annularcuff surrounds the exterior surface adjacent to the first end of thefirst cylinder. The plurality of sutures are threaded over the exteriorsurface of the first cylinder and over an interior surface of a secondcylinder. Pressure then is applied against the first cylinder, andtension is applied to the plurality of sutures to ensure a blood-tightseal between the cuff of the valve sleeve and the annulus. Finally, themethod comprises the steps of securing the plurality of sutures betweenthe first cylinder and the second cylinder by engaging the firstsecuring means of the first cylinder with the second securing means ofthe second cylinder and trimming the sutures, as described above.

Although the invention has been described in the specification anddrawings with respect to preferred embodiments, the invention is notlimited to these preferred embodiments, but its true scope and spiritare defined be the following claims. The specification is intendedmerely to be exemplary of the invention, and persons skilled in the artwill understand that modifications or alterations to the variousfeatures and components are possible without deviating from the scopeand spirit of the invention.

1. An apparatus for automatically fixing sutures used in the surgicalreplacement of a heart valve, comprising: a first cylinder having afirst end and a second end and an interior surface and an exteriorsurface; first means for securing fixing suture formed on said exteriorsurface adjacent to said second end of said first cylinder; and a secondcylinder having second means for securing fixing suture formed on aninterior surface of said second cylinder, such that said second meanscorresponds to and fixedly engages said first means for securing fixingsuture, wherein said first means and said second means secure fixingsutures therebetween.
 2. The apparatus of claim 1, wherein said firstmeans is an annular lip and said second means is an annular groove. 3.The apparatus of claim 1, wherein said first means is an annular grooveand said second means is an annular lip.
 4. The apparatus of claim 1,further comprising a valve sleeve comprising an annular cuff and aplurality of securing struts surrounding said exterior surface adjacentto said first end of said first cylinder, said struts extending beyondsaid first end of said first cylinder.
 5. The apparatus of claim 4,further comprising a replacement heart valve positioned within saidvalve sleeve and having a circumferential outer edge, wherein saidcircumferential outer edge is affixed to said valve sleeve.
 6. Theapparatus of claim 4, wherein said valve sleeve is manufactured from asurgical fabric.
 7. The apparatus of claim 5, wherein said replacementheart valve comprises a heart valve harvested from a human donor.
 8. Theapparatus of claim 5, wherein said replacement heart valve comprises aheart valve harvested from a pig.
 9. The apparatus of claim 5, whereinsaid replacement heart valve comprises a prosthetic heart valve.
 10. Anapparatus for automatically fixing sutures used in the surgicalreplacement of a heart valve, comprising: a first cylinder having afirst end and a second end and an interior surface and an exteriorsurface and a valve sleeve including an annular cuff; wherein saidsleeve surrounds said exterior surface adjacent to said first end ofsaid first cylinder, and wherein first means for securing fixing sutureare formed on said exterior surface adjacent to said second end of saidfirst cylinder; and a second cylinder having second means for securingfixing sutures formed on an interior surface of said second cylinder,such that said second means corresponds to and fixedly engages saidfirst means for securing fixing sutures, wherein said first means andsaid second means secure fixing sutures therebetween.
 11. The apparatusof claim 10, wherein said first means is an annular lip and said secondmeans is an annular groove.
 12. The apparatus of claim 10, wherein saidfirst means is an annular groove and said second means is an annularlip.
 13. The apparatus of claim 10, wherein said cuff is manufacturedfrom a surgical fabric.
 14. The apparatus of claim 10, furthercomprising a prosthetic heart valve positioned within said firstcylinder and affixed to said valve sleeve.
 15. An apparatus forautomatically fixing sutures used in the surgical replacement of a heartvalve, comprising: a first cylinder having a first end and a second endand an interior surface and an exterior surface; a valve sleevecomprising an annular cuff surrounding said exterior surface adjacent tosaid first end of said first cylinder, first means for securing fixingsuture formed on said exterior surface adjacent to said second end ofsaid first cylinder; and a second cylinder having second means forsecuring fixing sutures formed on an interior surface of said secondcylinder, such that said second means corresponds to and fixedly engagessaid first means for securing fixing sutures, wherein said first meansand said second means secure fixing sutures therebetween.
 16. Theapparatus of claim 15, wherein said first means is an annular lip andsaid second means is an annular groove.
 17. The apparatus of claim 15,wherein said first means is an annular groove and said second means isan annular lip.
 18. The apparatus of claim 15, further comprising areplacement heart valve positioned within said valve sleeve. sutures.19. An apparatus for automatically fixing sutures used in the surgicalreplacement of a heart valve, comprising: a first cylinder having aninterior surface; a second cylinder having an exterior surface; andmeans for securing said interior surface of said first cylinder to saidexterior surface of said second cylinder, wherein said means forsecuring comprises an annular lip formed on said interior surface ofsaid first cylinder and an annular groove formed on said exteriorsurface of said second cylinder.
 20. An apparatus for automaticallyfixing sutures used in the surgical replacement of a heart valve,comprising: a first cylinder having an exterior surface; a secondcylinder having an interior surface; and means for securing fixingsutures and for securing said exterior surface of said first cylinder tosaid interior surface of said second cylinder, wherein said means forsecuring comprises an annular groove formed on said exterior surface ofsaid first cylinder and an annular lip formed on said interior surfaceof said second cylinder, and wherein said annular groove and saidannular lip fix sutures therebetween.